Piercing point



June 19, 1934.

PIERCING POINT Filed March 6, 1951 4660876507. fDW/N C. WE/GH E. c. WRIGHT I 1,963,319

Patented June 19,. 1 93 4 UNITED STATES PATENT. OFFICE PIERCING POINT Edwin C. Wright, Ellwood City, Pa., assignor to National Tube Company, a corporation of New Jersey Application March 6, 1931, Serial No. 520,668

5 Claims.

high chromium and high chromium nickel alloys of the stainless type for the purpose of making seamless tubes due to the failure of the ordinary piercing plugs or points.

The novel alloy piercing point of this invention is capable of successfullypiercing high chromium and high chromium nickel alloys and when heat treated in accordance with the method herein set forth its life is materially increased and the quality of pierced work is improved.

In the drawing:

The several figures show plan views of several types of piercing points or plugs which have been made in accordance with this invention and successfully operated.

The plug or point A of Figure 1 is one type of point for use with a thirty-six inch roll piercing mill. The point A is composed of an' integral casting of the special alloy to be described below and comprises a point portion 2, a tapered body portion 3, and a sleeve or neck portion 4 of less diameter than the body and adapted to receive the forward end of the plug-bar of the mill.

- The plug or point B of Figure 2 is another type of point for use with the thirty-six inch roll piercing mill. The point B is generally of. a smaller diameter than the point A and is for piercing smaller billets. The point B consists of a tapered body 5 and a neck or sleeve 6 having a bore 7 which is extended into thebody 5 of the point to receive the end of the plug-bar.

The plug or point C of Figure 3 is for use with a disk type of piercing mill and comprises a long tapered nose portion 9 and a body portion 10 composed of a relatively short straight portion 12 and a rearwardly tapered. portion 13. n The portion 13 is provided with a bore 14 to receive the end of the usual plug-bar.

Plugs or points like those described above or any other design of plug or point for piercing I mill operations, when made in accordance with this invention, are particularly adapted for use in piercing high chromium or high chromium nickel steel alloy of the stainless type.

The plugs or points of this invention are cast from an alloy having the following analysis:

Carbon"; 1 per cent Chromium 15 to 20 per cent Nickel 3. to 6 percent Manganese -.40 to .60 per cent Silicon .25 to .50 per cent Sulfur under .05 per cent Phosphorus. under .04 per cent Iron to make 100 per cent A preferred specific alloy for the plugs or points has the following analysis: L

Carbon 1 per cent Chromium 17 per cent Nickel -Q 4.5 per cent Manganese"; .50 per cent Silicon .35 per cent Sulfur under .05 per cent Phosphorus .under .04 per cent- Iron to make 100 per cent After the points are cast from the alloy set forth above they are heat treated by quenching from a. temperature of 1050 centigrade in water. This heat treatment serves to materially increase the wearing qualities of the point and the quenching may be done while the points are 3 hot from the casting operation or after a reheating operation, as desired.

After the points have been quenched, as above set forth, they are preferably heated to a red heat, that is, to approximately 800 centigrade prior to using them in a piercing operation. This last heating operation is essential since it has been found that it cold pointsare used in piercing they will crack due to the sudden change in temperature. cracking is prevented by heating the-alloy points to a red'heat. While I have shown and described certain, specific forms of piercing plugs or points it will be understood that I do not wish Tobe limited thereto since this invention is applicable 'to any the scope of my invention, as defined in the appended claims.

I claim:

1. An alloy cast piercing point for use with high chromium or high chromium nickel alloys composed of a ferrous alloy having the following anaIysis-carbon approximately 1 per cent., chromium approximately 17- per cent., nickel approximately 4.5 per cent., manganese approximately .50 per cent.,silicon approximately .35 per cent., sulfur under .05 per cent., and phosphorus under .04 per cent., said point being given a preliminary heat treatment by quenching from a temperature of approximately 1050 centigrade in water.

2. An alloy cast piercing point for use with high chromium or high chromium nickel alloys composed of a ferrous alloy having the following analysis-carbon approximately 1 per cent., chromium approximately 1'7 per cent., nickel approximately 4.5 per cent., manganese approximately .50 per cent., silicon approximately .35 per cent., sulfur under .05 per cent., and phosphorus under .04 per cent., said point being given a preliminary heat treatment by quenching from a temperature of approximately 1050 centigrade in water and again heated to a red heat prior to use in a piercing operation.

3. An alloy cast piercing point for use with high chromium or high chromium nickel alloys composed of a ferrous alloy having the following analysis-carbon approximately 1 per cent., chromium approximately 17 per cent., nickel approximately 4.5 per cent., manganese approximately .50 per cent., silicon approximately .35 per cent., sulfur under .05 per cent., and phosphorus under .04 per cent., said point being given a preliminary heat treatment by quenching from a temperature of 1050 centigrade inwater, and again heated to approximately 800 centigrade prior to use in a piercing operation.

4. The method of heat treating cast piercing points for use with high chromium or high chromium nickel alloys composed of an alloy having the following analysis-carbon approximately 1 per cent., chromium 15 to 20 per cent., nickel 3 to 6 per cent., manganese .40 to .60 per cent., silicon .25 to .50 per cent.,' sulfur under .05 per cent., and phosphorus under .04 per cent., which includes casting said points, quenching said points from a temperature of approximately 1050 centigrade in water, and then reheating said quenched points to a red heat prior to using said points in a piercing operation and maintaining said points at said heat when starting said piercing operation.

5. The method of heat treating cast piercing points for use with high chromium or high chromium nickel alloys composed'of an alloy having the following analysis-carbon approximately 1 per cent., chromium 15 to 20 per cent., nickel 3 to 6 per cent., manganese .40 to .60 per cent., silicon .25 to .50 per cent., sulfur under .05 per cent., and phosphorus under- .04 per cent., which includes casting said points, quenching said points from a temperature of approximately 1050 centigrade in water, and then reheating 

